To clarify: you currently have a setup with a Pi connected to a MCP23017 via I2C, and the MCP23017 is driving your LED bar, correct?
Can you follow the SKPang demo code: http://www.skpang.co.uk/blog/wp-content/uploads/2012/06/ledchaser.py It uses the Python smbus module to talk to the I2C driver (SMBus and I2C are *basically* the same thing in this scenario). To understand it, you have to learn about the standard I2C protocol for reading/writing registers on a device (see Greg's email), and then look at the MCP23017 datasheet to figure out what each register does. On Wed, Nov 14, 2012 at 11:41 AM, Ming kuo <[email protected]> wrote: > Hi Guys, I was recently introduced to this group, so here is my first post. > > I work/volunteer at the Southend Technology Center in Boston. We teach > technology to kids and adults fostering interest in technology for kids and > enabling adults to be more competitive in the workforce. We were the > original Fab Lab initiated by MIT, and continue to have a strong > relationship with MIT. We have laser cutters, shopbot, broken 3D printer, > and teach kids to work with arduino. > > I manage the computer hardware repair workshop. > > So I have taken on a project (over my head) using old computer parts and > raspberry Pi. I am trying to build a POV sign that can gather data from > the net/cloud/remotely. > > I have followed this example http://www.skpang.co.uk/blog/archives/454 to > get LEDs controlled by a raspberry. But now like to convert this to using > this http://adafruit.com/products/459 a bi-color 12 bar led (for more > colors and cleaner product) > > I figured out the wiring to get the bar to light up using the same codes > as above. So I am now ready to control the LED bar, and that is where I am > stuck...on the python code to control the I2C. I think my too basic > knowledge of electronics and programming would be benefited by someones > help. This is my immediate challenge to figure out how to program the I2C > for the LED bar, then eventually, I need to program a python code to POV > display the messages which i can imaging that it get pretty challenging > given how to form a character with LED while timing the rotation. > > So I am looking for someone who maybe familiar with I2C to offer insight > and hopefully someone that has time to tinker on this project along with > me. I am at the tech center typically in the afternoons till 8PM at 359 > Columbus Ave in the Southend. > > So any help through email or in person would be greatly appreciated. > > Thanks > > Ming > > _______________________________________________ > Hardwarehacking mailing list > [email protected] > http://lists.blu.org/mailman/listinfo/hardwarehacking > >
_______________________________________________ Hardwarehacking mailing list [email protected] http://lists.blu.org/mailman/listinfo/hardwarehacking
